package com.woniuxy.shiro.utils;

import org.apache.shiro.web.filter.authc.BasicHttpAuthenticationFilter;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class JWTFilter extends BasicHttpAuthenticationFilter {
    //跨域支持
    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
        httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
        httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("Access-Control-Request-Headers"));
        // 跨域时会首先发送一个option请求，这里我们给option请求直接返回正常状态
        if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())){
            httpServletResponse.setStatus(HttpStatus.OK.value());
            return false;
        }
        return super.preHandle(request,response);
    }
    //返回true false无法见
    @Override
    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
        System.out.println("isAccessAllowed，判断用户是否登录！");
        if(isLoginAttempt(request,response)){
            try{
                //如果有token
                executeLogin(request,response);
            }catch (Exception e){
                response401(request,response);
            }
        }
        return true;
    }

    //判断用户是否想要登录
    @Override
    protected boolean isLoginAttempt(ServletRequest request, ServletResponse response) {
        System.out.println("进入isLoginAttempt方法，判断用户是否登录！");
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        String authorization = httpServletRequest.getHeader("Authorization");
        return authorization != null;
    }


    @Override
    protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        //从请求头中获取token
        String authorization = httpServletRequest.getHeader("Authorization");
        //放入对象中，redis或者数据库查询，等同于之前usernamepasswordToken
        MyJsonWebToken token = new MyJsonWebToken(authorization);
        //提交给realm进行登入，如果错误，抛异常
        System.out.println("JWTFilter.executeLogintoken交给realm判断:"+token);
        //等同于直接login
        getSubject(request,response).login(token);
        //成功返回true 失败就抛异常
        return true;
    }
    //非法请求跳转到这
    private void response401(ServletRequest req, ServletResponse resp) {
        try {
            HttpServletResponse httpServletResponse = (HttpServletResponse)resp;
            httpServletResponse.sendRedirect("/401");
        }catch (IOException e){
            System.err.println(e.getMessage());
        }
    }
}
